Strings with hh:mm format

Question

I have two hh:mm strings, and I want to make comparisons between them.

I mean, I would want to add or subtract them, make operations. I have a string with the current time and another string that says, for example, "15:00". I want to know how many minutes there are between both strings, result that I can take by doing a subtraction. Is that possible?

Yes it is possible. However there are many resources on the net which can help you with this. SO is a Q & A site. No a tutorial request. Sorry if im being rude but its the truth — MarsOne, Sep 03 '13 at 13:56
Read about [Date](http://docs.oracle.com/javase/6/docs/api/java/util/Date.html) and [SimpleDateFormat](http://download.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html) — rocketboy, Sep 03 '13 at 13:57
Convert to minutes and then you can easily add/substract/compare — NeplatnyUdaj, Sep 03 '13 at 14:01

Mauren · Answer 1 · 2017-01-18T16:25:07.687

3

You can parse it by using SimpleDateFormat, then use the getTime() method from Date class to obtain the difference in milliseconds.

DateFormat f = new SimpleDateFormat("hh:mm");
Date d1 = f.parse(s1);
Date d2 = f.parse(s2);
long difference = d1.getTime() - d2.getTime(); // milliseconds

edited Jan 18 '17 at 16:25

answered Sep 03 '13 at 14:00

Mauren

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Venkata Krishna · Answer 2 · 2013-09-03T14:49:27.367

0

This will get you started.. Do the following for the two strings & then do the necessary comparisions/add/subtract

String time1 = "15:00";
String time2 = "16:00";

DateFormat sdf = new SimpleDateFormat("hh:mm");
Date date1 = sdf.parse(time1);
Date date2 = sdf.parse(time2);

long milliSecondsDiff = date1.getTime() - date2.getTime(); //in milliseconds
int seconds = milliSecondsDiff/1000; //seconds
int minutes = seconds/60; //minutes

edited Sep 03 '13 at 14:49

answered Sep 03 '13 at 13:57

Venkata Krishna

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You can use `a.getTime() - b.getTime()` to get the difference in milli-seconds. – Peter Lawrey Sep 03 '13 at 13:59
@PeterLawrey absolutely.. didn't want to give it away before OP posts some code.. thanks – Venkata Krishna Sep 03 '13 at 14:50

score 0 · Answer 3 · answered Sep 03 '13 at 14:01

You could use joda datetime for this:

public static void main(String[] args) {

    DateTimeFormatter formatter = DateTimeFormat.forPattern("HH:mm");
    DateTime first = formatter.parseDateTime("15:00");
    DateTime second = formatter.parseDateTime("15:49");

    Interval interval = new Interval(first, second);
    System.err.println(interval.toDuration().getStandardMinutes());
}

Have a look here

Using Duration also gives you some other neat methods like getStandardSeconds() which would give you 2940 for this case.

Strings with hh:mm format

3 Answers3